JPosture

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J-SHOES

J-shoes are biofeedback shoes that track weight distribution between the feet.

How they work

Each shoe has four pressure sensors—two in the front and two in the heel. The system ensures proper stance by comparing the front sensors of both feet and the heel sensors of both feet. Ideally, these values should be as similar as possible.

Each shoe has its own microcontroller, with the right shoe acting as the main controller. This prototype uses Arduino Micros. The right shoe receives sensor data from the left shoe and compares it with its own readings. If the values stay within an acceptable range, nothing happens. However, if the difference exceeds the threshold for a set duration, the right shoe signals to the left shoe to vibrate, prompting the wearer to adjust their stance.

Bluetooth communication

The shoes connect via Bluetooth. The left shoe has one HC-05 module to communicate with the right shoe, while the right shoe has two modules—one to talk with the left shoe and the other to transmit data to the phone app.

J-Shoes Android App

The right shoe communicates with an Android app, sending pressure sensor readings and the percentage difference between foot pressures while also receiving settings from the user. The app visually displays this data and allows real-time adjustments to the shoe’s functionality.

Two adjustable sliders control the shoes from the phone:

Acceptable Percentage Difference: Sets the allowed pressure imbalance between sensor groups, ranging from 10% to 50%. For example, at 50%, one foot could exert twice the pressure of the other before triggering a response.

Seconds Permitted: Determines how long the acceptable difference can be exceeded before the shoe vibrates, reminding the wearer to correct their stance.

If the imbalance surpasses the set threshold for the defined duration, the right shoe signals the left shoe to vibrate, prompting posture correction.

Circuitry

In this prototype the circuit layout is identical for both shoes, except the right shoe has two switches. Both shoes are switched on so their Bluetooth modules pair, then the Bluetooth module for the phone is turned on for them to pair.

Longterm potential: NONE

Conclusion and considerations

Limitations

• Awfully high latency due to slow speed of microcontrollers as well as their configuration...Not to mention running multiple Bluetooth modules transmitting in either duplex or unidirectionally.
• The App interface was 2D. Not only was it boring...but it was completely impossible to consider and appreciate the data in real-time. Absolutely must be graphical.

Road ahead

I learned a lot throughout the process, which led to the development of the ARGait shoes. ARGait have not only solved all previous issues but also opened up multiple new paths for future development.